Manufacture of gelatinous compositions for use in the reproduction of line documents



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No Drawing.

Dorel process, ferro-gelatinography, gela-- tin process, paste process,ozofer process,

'ordoverax process, etc., the working of which is as follows:

A gelatin composition previously melted in a water bath is spread on asheet of zinc, copper or aluminium or on glass, marble, linoleum, etc.When the composition has set, a blue print (ferro-prussiate' paper)which has been previously 'ex posed behind the original or tracing to bereproduced so as to obtain a photographic. image of the latter, isapplied to the surface. This blue print which is an exact image of theoriginal, is applied to the composition dry, that is to saynon-developed or fixed by water. As a result, a chemlcal reaction takesplace 1nstantaneously between the gelatin composition and those parts ofthe sensitive paper which have not been exposed to light and correspondto the writing, lines, etc. on the tracing.

There" is produced in short on the gelatin composition a photographictransfer of the original to be reproduced, which transfer constitutes ablock that can be inked with printers ink. The inking having been done,it is suflicient to apply to the block a sheet of paper and to exercisea slight pressure in order to obtain a copy of the original. Many copiescan be so obtained.

In the said process the gelatin composition always comprises twoundamental products: gelatin, and a metal salt such as ferrous sulfate.It is also possible to add glycerin, formol, quinone, quinone sulfonateof sodium, alums, etc.

The gelatin composition obtained in the above mentioned manner is abrown or reddish-brown or yellow-brown or yellow mass. After it hasbeenspread on the support, its color persists, but gradually be-Specifieation of Letters Patent.

Patented Aug. 9, 1921.

Application filed. December 2, 1918. Sierial No. 265,033.

comes less strong as the layers become thinner. Certain compositionsbecome even practically transparent. This results in insufficientlegibility of the inked block, more particularly in th case of inkshaving a color approaching that of the gelatin compos tion, or a badinter retation of the colors deposited by the in ing roll. Moreover,certain accidents which happen fairly frequently in the course ofworking, such as partial doudingflnk lines deposited by the edges of theinking roll, various stains which do not form part of the drawing, andwhich are reproduced in the copy, are diflicult for the operator tonotice when .he has not had a long experience with the process.

he present invention makes it possible to avoid these various drawbacks.The invention comprises a white gelatin composition which can be usedfor the reproduction of drawings, maps, plans, manuscripts, music, etc.If to the usual composition is added a white substance such as forinstance white of baryta, kaolin, etc., or any other substance whichdoes not exercise any action on the gelatin, or if, in the interior ofthe gelatin mass, there is produced by a double decomposition process, awhite precipitate (barium sulfate, carbonate of lead etc), a whitegelatin composition will be obtained which has all the properties of theusual composition, but offers advantages which do away with all thedrawbacks above referred to.

The learning and the use of the process are then facilitated, since inworking on a white background, the operator notices at once the leastclouding, or the smallest stain.

A gelatin composition which gives good results, is obtained in thefollowing man ner:

Melt in a water bath 100 gr. gelatin and 200 gr. water. The meltinghaving been completed, add successively with .constant stirring thefollowing hot solutions:

100 gr. water, 70 gr. sodium sulfate, gr. water, 40 gr. barium chlorid,

then- 20 gr. water, 1.5 gr. ferrous sulfate.

can'm'oreoverbe brought about by means of other substances, providedthat it leaves as the result a white preci itate. Glycerin, formol,alums, etc, can e added to the composition without afi'ecting its color.

The composition prepared as stated above can be used in the usualmanner.

What I claim is:

1. A gelatinous composition for use in the reproduction of linedocuments, formed of gelatin, ferrous sulfate, and substances adapted toproduce in the interior of the composition a white precipitate by adouble decomposition process, for the purpose described.

2. A gelatinous composition for use in the reproduction of linedocuments, said composition consisting of gelatin, ferrous sulfate and awhite substance which exerts no chemical action on the gelatin for thepurpose described.

3. A gelatinous composition for use in the reproduction of linedocuments, said composition consisting of gelatin, ferrous sulfate andsubstances adapted to produce in the interior of the composition a whiteprecipitate by a double decomposition process, for the purposedescribed.

4. A white gelatinous composition consisting of gelatin, ferrous sulfateand a substance for whitening said composition by double decompositionthereof adapted, upon being formed intoa printing block and havingreceived an imprint from a llned document, to retain printers ink forrepeatedly reproducing said lined document.

5. A method of manufacturing a white gelatinous composition for use inthe reproduction of line documents, consisting in first melting 100grams gelatin in 200 grams water; second, adding hereto while stirring ahot solution of 70 grams sodium'sulfate in 100 grams water; third,adding in similar manner a hot solution. ofAO grams barium chlorid in 80grams water; lastly adding in similar manner a hot solution of 1.5 gramsferrous sulfate in 20 grams Water.

6. A method of manufacturing a white gelatinous composition for use inthe production of line documents, consisting in first melting gelatin inwater; second adding hereto while stirring a hot solution of sodiumsulfate in water; third, adding in a similar manner a hot solution ofbarium chlorid in water; lastly, adding in a similar manner a hotsolution of ferrous sulfate in water. 1

In testimony whereof I aflix my signature in presence of two witnesses.

